Process of obtaining nitro compounds



F. B. HOLMES.

PROCESS OF OBTAINING NITRO COMPOUNDS.

APPLICATION FILED MAY II. 1915.

Putcntvd July 8, 191%) \H N INVENTOR 4 ITO/M578 UNITED STATES PATENT orruon.

FLETCHER B. HOLMES, OF WOODBURY, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO E. I. no PONT DE NEMOURS AND COMPANY, A CORPORATION DELAWARE;

PROCESS OF OBTAINING NITRO COMPOUNDS.

Patented July 8, 1919.

Application filed Kay 11, 1915. Serial No. 27,301.

naturally and after various treatments to which they are subjected in theirrefining, contain nitrifiablehydrocarbons 1n dlfi'ermg amounts, while the main body of the petroleum products is usually incapable of nitration with nitric acid or mixtures of nitric the petroleum products may be aromatic hyand sulfuric. acids to form useful nitrocompounds.

The' nitrlfiable constituents in drocarbons, such as benzol, toluol, xylol, etc.

The nitrifiable constituents may be acted upon to form mono, dior possibly trinitro-compounds or mixtures of the same, and nitro-compounds thus formed may be separated from the remaining constituents in the petroleum products.' Where this s done in the usual way, however, that is to say, by mixing the petroleum products and the acids in a nitrating vessel in the usual way, the relatively larger volume of nonnitrifiable petroleum products results in a low capacity of the nitrating unit in output of nitro compounds.

The object of my invention is to provide a process for obtaining the nitro-compounds in question in an efiective manner by the. rapid nitration of the constituents of the petroleum products which are capable of; being acted upon by the nitrating acids. 9

I have discovered that the nitration can be effectively accomplished by forcing the petroleum products into a vessel at the bottom thereof which contains a mixture of the nitric and sulfuric acids. In this way the petroleum products will pass upwardly through the body of acids and during the passage of the same through the acids may or may not be agitated as desired. The pe- 'troleum products because of their low denvery effective manner.

sity rise rapidly through the acids, and the height of the'container for the acids may be made sufficiently great to accomplish the nitration of the nitrifiable constituents in a; The nitro products thus formed accumulate partly on the surface of the acids where they are dissolved 1n or 1n contact with the unnitrated petroleum products while a portion of the nitrocompounds also remains with the body of the acids. The separate layer of nitro-compounds and petroleum products on the top of the body of acids may be drawn ofi' continuously and the unnitrated petroleum products separated from the( nitro compoundsby distillation. The layer of acids containing the'remainder of the nitro-compounds may then be allowed to stand so as toseparate the nitro-compounds from the spent acid. The upper layer which comprises the nitro-compounds is drawn off, washed, neutralized and dried in the usual way. The process is preferably conducted with the use of a condenser so as to prevent the escape of gasolene vapors during the process. In carrylng out my invention furthermore,I find 1t advantageous to feed the acids}:in'at the top of the nitrating vessel at a unlform rate and to draw off the same at the bottom thereof at the same rate, the conditions being so controlled as to substantially prevent the acids leaving the bottom of the vessel from carrying with them any unnitrated petroleum products. The acids discharged from, the vessel do, however, carry out some of the nitro-compounds. When operating. in this manner it is preferable also to feed in the petroleum products continuouslynear the bottom of the nitrating vessel, and draw off the same with a quantity of the nitro-compounds at the top of the vessel.

While my invention is capable of embodiment in many different forms, for the purpose of illustration I have described only one form of my inventionherein, and have shown only one form of apparatus for use in connection with my process in the accompanying drawings, in which The figure represents diagrammatically an apparatus with which my invention is capable of being carried out.

In the drawings I have shown a nitrating vessel 1, having a valved inlet pipe 2, near the top thereof for mixed acidss'supplied to the nitrating vessel from an acid tank 3. This acid tank 3 is adapted to receive its supply of mixed nitric and sulfuric acids by means of-a pipe 4: leading from a pump of any suitable construction. This pump 5 receives its acids from a valved pipe 6 which leads'from an acid and nitro-compound separating tank 7 and which is provided with a valved draw-off pipe 8. T be mixed acids which are fed into the nitrating vessel 1, pass downwardly in a continuous stream through the same and after coming into contact with the hydrocarbons therein are discharged through a valved pipe 9 into the separating tank 7. \Vhile the downward current of heavy mixed acids is thus produced in the nitrating chamber 1, an oppositely, that is to say upwardly, moving current of the hydrocai bons is produced there.

in by forcing 'gasolene from a tank 10 provided with air pressure, through a valved pipe 11 and a spraying nozzle 12 connected to said pipe 11 located in the lower part of the nitrating vessel 1. The gasolene which passes upwardly through the body of acids in the nitrating vessel 1, passes over cooling pipes 12 and accumulates in a layer 13 over the top of the acids; in the nitrating chamber 1, together with a quantity of the nitrocompounds dissolved in or in contact with the body of hydrocarbons in said layer 13. The mixed hydrocarbons and nitro-compounds are drawn off from this layer 13 by a pipe 14 to a condenser 15, which condenses any volatilized hydrocarbons. The mixed gasolene and nitro-compounds pass out of the condenser 15 into one of the tanks 16 and 17 by means of the valved pipes 18 and 19 communicating therewith, where they are Washed with a dilute alkaline solution to neutralize any acid remaining'therein, and then with water to free the same from alkali. The waste water from the tank 16 and 17 is discharged through a. valved pipe 20 Which communicates with discharge pipes 21 and 22 located on the tanks 16 and 17 -respec-' tively. The gasolene and nitro-compound-s are thereafter run into a still 23 by means of valved pipes 24 and 25 from the tanks 16 and 17. The liquids thus introduced into the still 23 are separated by the application of heatin any desired manner, preferably while subjected to a current of steam or-inert gas from a pipe 26 located in the bottom of the still, thus distilling off the unnitrated gasolene through a pipe 27 which passes into a condenser 28 and thence into a gasolene storage tank 29. Preferably a reduced pressure is maintained in the still 23 by means of a pump 29 connected by a pipe to the discharge end of thecondensing coil 28. The nitro-compounds thus remaining in the still 23, are drawn otf from the same bv means of a valved pipe 31, through which from the nitrating vessel 1, and which accumulate in the tank 7, also contain a percentage of the intro-compounds, the acids in the tank 7 are allowed to stand until the nitro-compounds therein accumulate in a layer 3% at the top of the tank 7, from which they are drawn off by means of a valved pipe 35 into the tank I In this way the nitro-compounds formed in the process, and which become dissolved in or which remain in contact with the 'nitrating acids and the unnitritied hydrocarbons, become collected at the same point. The nitro-hydrocarbons which thus accumulate in the tank 32 may be neutralized and washed in the usual way.

Although I have described the use of a. mixture of sulfuric and nitric acids for removing the nitrifiable constituents from petroleum products it should be understood that nitric acid alone can also be used under certain conditions though ordinarily the use of a mixture of nitric and sulfuric acids gives more satisfactory results.

\Vhile have described my invention above in'detail, I wish it to be understood that many changes may be. made therein without departing from the spirit of my invention. i

I claim:

1. The process which comprises forming a intro-compound by passing a hydrocarbo n liquid containing nitrifiable and a relatively large proportion of non-nitrifiable constituent upwardly through a nitrating acid. v

2. The process which comprises forming a IIIt-IO-COIIIPOlllltl by passing a petroleum product containing a small amount of a nitrifiable aromatic constituent and a nonnitrifiable constituent upwardly through a nitrating acidQdrawing off the petroleum product from above the surface of the acid and recovering the nitro-(TGnipounds formed.

3. The process which comprises forming a nltro-compound by passing a petroleum product, contz'iining a nitrifiable constituent upwardly through a downwardlv moving current of a nitrating acid. I

4:. The process which comprises forming a nitro-compound by passing a petroleum product containing a nitrifiable constituent upwardly through a downwardly moving current of a nitrating acid, drawing off the petroleum product from above the surface of the acid and recovering the nitro-compounds formed.

5. The process whicli comprises forming a intro-compound by passing a petroleum product containing a small amount of a nitrifiable aromatic constituent and'anonnitrifiable constituent upwardly through a nitrating acid, drmving'ofl thepetroleum product from above the surface of the acid and the acid from a point below the petroleum product and recovering the nitrocompounds formed.

(3. The process which comprises forming a nitro-coinpound by passlng a petroleum product containing a nitrifiable constituent upwardly through a downwardly moving current of a nitrating acid, drawing off the petroleum )roduct from above the surface of the acid and the acid from a point below the petroleum product and recovering the nitro-compounds formed.

7. The process which comprises forming a nitro-compound by passing a petroleum product containing nitrifiable and non-nitrifiable constituents upwardly through a nitrating acid, drawing off the petroleum product from above the surface of theacid and recovering the intro-compounds formed by distillation.

8. The process which comprises forming a intro-compound bv passing a petroleum product containing a nitrifiable constituent upwardly through a downwardly moving current of a nitrating acid, drawing off the petroleum product from above the surface of the acid and recovering the nitro-compounds formed by distillation.

9. The process which comprises forming a nitro-compound by passing a petroleum product containing a nitrifiable constituent and a relatively large proportion of a nonnitrifiable constituent upwardly through a nitrating acid, drawing off the petroleum product from above the surface of the acid and the acid from a point below the'petroleum product and recovering the nitrocompounds formed by distillation.

10. The process which comprises forming a. nitro-compound by passing a petroleum product containing a nitrifiable constituent upwardly through a downwardly moving current of a nitrating acid. drawing oti' the petroleum product from above the surface of the acid and the acid from a point below the petroleum product and recovering the nitro-cmnponnds formed by distillation.

11. The process which comprises forming a nitro-compound by passing a petroleum product containing a nitrifiable constituent upwardly through a nitrating acid, drawing ofl' the petroleum product from above the surface of the acid and the acids from a petroleum product from above the surface.

of the acid and the acid from a point below the petroleum product and recovering the nitro-compounds formed by distillation of the nitrocompounds from the unnitrated constituents of the petroleum product associated therewith and separation by gravity of the nitro-conipounds from the acids associated therewith.

'13. The process which comprises forming a nitro-compound by passing a petroleum product containing a nitrifiable constituent upwardly through a nitrating acid, drawing ofi the petroleum product from above the surface'of the acid and recovering the nitlO-COll'lPOlllltlS formed by distillation with the injection of steam.

14. The process which comprises forming a nitro-compound by passing a petroleum product containing a nitrifiable constituent upwardly through a downwardly moving current of a nitrating acid, drawing otf the petroleum product from above the surface of the acid and recoverin the nito-compounds formed by distillation with the injection of steam.

15. The process which comprises forming a nitro-coinpound by passing a petroleum product containing a nitrifiable constituent upwardly through a nitrating acid, drawing off the petroleum product from above the surface of the acid, while subjecting the same to condensation and recovering the nitro-compounds formed.

In testimony that I claim the foregoing I have hereunto set my hand.

FLETCHER B. HOLMES.

Vitnesses Gnome E. PIERSON, ANNA L. ESTELL. 

